The present invention relates to a flexible container having a support system comprising internal baffles for assisting in maintaining the shape of the container when it is filled with a material.
Flexible containers are commonly used for the handling, storage and transportation of flowable materials. These containers are typically designed to be rectangular in cross-section so that they form xe2x80x9ccubesxe2x80x9d when filled which can be packed efficiently into storage and transportation facilities such as trucks and warehouses, minimizing the amount of wasted space that may result from other shapes.
Unfortunately, flexible containers have an inherent tendency to bulge when filled so that they do not maintain their intended shape. This bulging typically results in the container having rounded corners and sides which are not straight. This in turn results in the containers being more difficult to handle and store efficiently.
It is well known in the art of flexible containers to employ devices or systems for adding structural support to the container for the purpose of assisting in maintaining the shape of the container.
For example, U.S. Pat. No. 5,076,710 (Derby), U.S. Pat. No. 5,165,802 (Derby), U.S. Pat. No. 5,222,812 (Cuddy et al), U.S. Pat. No. 5,328,267 (Cuddy et al), U.S. Pat. No. 5,468,528 (Shnaars et al), U.S. Pat. No. 5,556,205 (Gallie), U.S. Pat. No. 5,564,833 (Proffitt) and U.S. Pat. No. 5,685,644 (Taylor) all describe the use of xe2x80x9ccorner bafflesxe2x80x9d which span adjacent sides of flexible containers in order to add support to the container. These corner baffles include apertures of a variety of shapes such as circles, rectangles, diamonds and triangles for permitting material to pass between sides of the baffles. A variety of different configurations for the baffles is described in these references, but all are attached such that in a rectangular shaped container, there are eight locations of connection between the baffles and the side walls of the container.
U.S. Pat. No. 5,071,025 (Boots), U.S. Pat. No. 5,289,937 (Boots), U.S. Pat. No. 5,407,090 (Boots), U.S. Pat. No. 5,562,227 (Takezawa et al), U.S. Pat. No. 5,618,255 (Nickell et al) and U.S. Pat. No. 5,649,767 (Nickell et al) all describe container systems that consist of outer structures and inner structures which together provide support for the container through the cooperation of the two structures. Once again, a variety of different configurations for the structures is described, but these container systems all tend to be somewhat complicated and thus would be difficult or costly to manufacture.
U.S. Pat. No. 5,316,387 (Polett et al), U.S. Pat. No. 5,328,268 (Lafleur), U.S. Pat. No. 5,421,804 (Lafleur), U.S. Pat. No. 5,538,155 (Hoekstra), U.S. Pat. No. 5,660,478 (Alack et al), and U.S. Pat. No. 5,664,887 (Lafleur) all describe types of support systems for flexible containers, some of which include baffle structures and some of which do not.
U.S. Pat. No. 5,316,387 (Polett et al) describes three different embodiments of a support system. In a first embodiment, a plurality of loops are attached to the inside surfaces of the walls of the container at a plurality of levels. A rope or the like is then passed through each loop at a level and the rope is then joined at its ends. Each loop is separately attached to a wall so that there are four attachment points per level for a four sided container. In a second embodiment, a plurality of panels are provided, each of which have one edge affixed to the inside surface of one wall of the container and extend toward the center of the container. The panels are then fastened together at a point at or near the center of the interior of the container to define a plurality of separate sections within the container. Material is permitted to move between sections at the upper and lower ends of the panels. A third embodiment is a hybrid of the first and second embodiments, and comprises a plurality of flaps, each of which have one edge affixed to the inside surface of one wall of the container. Each flap has a plurality of holes at a plurality of levels. A rope or the like is passed through each of the holes at a level and the rope is then joined at its ends. The support system in Polett therefore involves a significant amount of fabrication effort.
U.S. Pat. No. 5,538,155 (Hoekstra) describes a support system somewhat similar to the hybrid embodiment in Polett in which a baffle xe2x80x9ccorexe2x80x9d is provided, which baffle core is contained within the container and is spaced from the inner surfaces of the walls of the container by side walls which extend from the inner surfaces of the walls toward the center of the container. The baffle core is therefore relatively small in comparison with the size of the container, and fabrication of the container and support structure is made somewhat more complicated by the inclusion of the side walls. Holes are provided in the baffle core to facilitate movement of material into and out of the baffle core.
U.S. Pat. No. 5,660,478 (Alack et al) describes a support system somewhat similar to the first and second embodiments in Polett. In Alack, a plurality of tension members are provided at different levels in the container. These tension members are attached to the walls of the container and either extend between opposite sides of the container or between adjacent sides of the container. As in Polett, the use of the tension members requires four connection points per level for a four sided container.
U.S. Pat. No. 5,328,268 (Lafleur), U.S. Pat. No. 5,421,804 (Lafleur) and U.S. Pat. No. 5,664,887 (Lafleur) all describe a support system for a flexible container which is similar to the first embodiment in Polett, in that closed loops of cord are provided around the inner surfaces of the walls of the container at a plurality of levels. These loops of cord preferably have portions which extend obliquely between adjacent sides of the container. In the preferred embodiment, the cords require a minimum of eight connection points to the walls of the container per level in order to provide the oblique portions, thus adding to fabrication costs.
All of the support systems for flexible containers as detailed above may add significant cost to the fabrication of the container due to the number and types of connections that must be used to attach the support system to the container.
In addition, the support systems detailed above which include apertured baffles often permit the passage of material through the baffle but only while compromising its structural support properties.
For example, in U.S. Pat. No. 5,076,710 (Derby), U.S. Pat. No. 5,165,802 (Derby), U.S. Pat. No. 5,468,528 (Schnaars et al), U.S. Pat. No. 5,556,205 (Gallie et al), U.S. Pat. No. 5,564,833 (Profitt) and U.S. Pat. No. 5,685,644 (Taylor) the baffles include a plurality of relatively large apertures spaced vertically along the centerline of the baffle. These large centralized apertures facilitate easy movement of the material through the baffle but tend to result in bulging of the container adjacent to locations where the apertures are positioned because the strength of the baffle is compromised at those locations.
In U.S. Pat. No. 5,222,812 (Cuddy et al), U.S. Pat. No. 5,328,267 (Cuddy et al), U.S. Pat. No. 5,538,155 (Hoekstra), the apertures tend to be smaller and more evenly distributed on the baffle, resulting in some improvement in the strength and thus the support properties of the baffle. This improvement in strength is offset, however, by the baffle providing a more restrictive passage for material due to the relatively small apertures.
U.S. Pat. No. 5,618,255 (Nickell et al) and U.S. Pat. No. 5,649,767 (Nickell et al) both describe the use of a plurality of xe2x80x9cbaffle stripsxe2x80x9d which are attached to a liner for the container with spaces between them to permit the passage of material around the strips. Each baffle strip can thus function as a separate support member, with the ability of material to pass around the baffle strips being governed by the spacing between the strips. Although the system described in Nickell addresses the issue of maintaining the support properties of the baffle, and although the width of the spacing between the strips could conceivably be adjusted to facilitate easy passage of material around the baffle strips, the Nickell system is relatively complicated and could as a result be quite costly to manufacture.
As a result, there remains in the art of flexible containers a need for a flexible container that is relatively easy to manufacture and yet incorporates a relatively efficient support system for assisting in maintaining the shape of the container when it is filled with a material.
The present invention relates to a flexible container of the type comprising a bottom, a plurality of flexible side walls and a plurality of flexible baffles. In particular, the invention relates to a flexible container of this type where each side wall is comprised of one baffle connection line and wherein each baffle is attached to two adjacent side walls along the baffle connections for those side walls.
In one aspect of the invention, the invention is a flexible container, the container comprising:
(a) a bottom;
(b) a plurality of flexible side walls projecting from the bottom, the side walls and the bottom together defining a container space for containing a material;
(c) one baffle connection line extending along each of the plurality of side walls; and
(d) a plurality of flexible baffles contained within the container space, wherein each baffle is attached to two adjacent side walls along the baffle connection lines for those side walls.
In another aspect of the invention, the invention relates to a method for constructing a flexible container of the type comprising a bottom, a plurality of flexible side walls projecting from the bottom, the side walls and the bottom together defining a container space for containing a material, and a plurality of flexible baffles contained within the container space, and is the improvement comprising attaching each baffle to two adjacent side walls along a single baffle connection line on each of the adjacent side walls.
The baffles are preferably attached to the side walls along seams on the side walls so that the seams comprise the baffle connection lines along those side walls to which baffles are attached. The seams on the side walls may be interior seams which are created from inside of the container space. Preferably, however, the seams on the side walls are exterior seams which are created from outside of the container space.
The baffles may be attached to the baffle connection line in any manner, including by gluing, melting, welding, riveting or stapling. Preferably, however, the baffles are attached to the baffle connection line by stitching them to create a seam so that the side walls and the baffles are attached by stitches which define the baffle connection line. The stitching is preferably performed from outside of the container space so that an exterior seam is formed.
The baffles may be attached to the side walls continuously or intermittently along the baffle connection line. The baffle connection line may extend the full height of the side walls or may extend for only a portion of the height of the side walls. Preferably, the baffle connection line extends along substantially the entire height of the side walls so that the baffles are attached to the side walls along substantially the entire height of the container.
The baffle connection lines on the side walls preferably extend in a direction substantially perpendicular to a plane defined by the bottom of the container and may be positioned at any location between the edges where side walls meet adjacent side walls. Preferably, however, the baffle connection lines are positioned approximately midway between the edges of the side walls so that the baffle connection lines substantially bisect the side walls.
The baffles together when attached to the side walls preferably define an interior baffle space within the container space and define an exterior baffle space within the container space. Preferably, the baffles are attached to the side walls such that the interior baffle space adjacent to the baffle connection line on each side wall extends substantially to the inner surface of the side wall.
The baffles may either include or not include apertures to facilitate the passage of material between the interior baffle space and the exterior baffle space. If no apertures are provided in the baffles, the baffles preferably are attached to the side walls such that material may pass underneath the baffles or over the top of the baffles.
Preferably, however, each of the baffles defines at least one aperture for permitting the material to pass between the interior baffle space and the exterior baffle space. More preferably, each of the baffles defines a plurality of baffle strips separated by apertures and preferably each of the baffle strips and apertures extends substantially between the baffle connection lines. Most preferably, the size of each baffle strip and each aperture is substantially the same.
The container may be comprised of any number of side walls and baffles which are capable of defining the container space. It is not necessary that the number of baffles equal the number of side walls. Preferably, however, the container is comprised of four side walls and four baffles. Each side wall and each baffle may be constructed of one panel or piece of material or may be constructed of more than one panel or piece of material. Furthermore, more than one side wall or baffle may be constructed from a single panel or piece of material.